Defining arrays in single line in Javascript

I am trying to declare multiple arrays in a single line. But I am taking this error. (Cannot set property "0" of undefined)

var photos,tags = new Array();

flickrJSON.items.forEach(function(item, index) 
 photos[index] = item.media.m;
 tags[index] = item.tags;
);

Why I take this error? Can somebody explain? and How can I fix it

asked Nov 15 '18 at 11:28

devneeddev

564

Can you use ES6?

– omri_saadon
Nov 15 '18 at 11:29

Just for the sake of interpreting the error, writing: var photos,tags = new Array(); is the same as writing var photos; var tags = new Array();. Hence the error (photos is undefined).

– briosheje
Nov 15 '18 at 11:34

add a comment |

I am trying to declare multiple arrays in a single line. But I am taking this error. (Cannot set property "0" of undefined)

var photos,tags = new Array();

flickrJSON.items.forEach(function(item, index) 
 photos[index] = item.media.m;
 tags[index] = item.tags;
);

Why I take this error? Can somebody explain? and How can I fix it

asked Nov 15 '18 at 11:28

devneeddev

564

Can you use ES6?

– omri_saadon
Nov 15 '18 at 11:29

Just for the sake of interpreting the error, writing: var photos,tags = new Array(); is the same as writing var photos; var tags = new Array();. Hence the error (photos is undefined).

– briosheje
Nov 15 '18 at 11:34

add a comment |

I am trying to declare multiple arrays in a single line. But I am taking this error. (Cannot set property "0" of undefined)

var photos,tags = new Array();

flickrJSON.items.forEach(function(item, index) 
 photos[index] = item.media.m;
 tags[index] = item.tags;
);

Why I take this error? Can somebody explain? and How can I fix it

asked Nov 15 '18 at 11:28

devneeddev

564

I am trying to declare multiple arrays in a single line. But I am taking this error. (Cannot set property "0" of undefined)

var photos,tags = new Array();

flickrJSON.items.forEach(function(item, index) 
 photos[index] = item.media.m;
 tags[index] = item.tags;
);

Why I take this error? Can somebody explain? and How can I fix it

javascript arrays declaration

asked Nov 15 '18 at 11:28

devneeddev

564

asked Nov 15 '18 at 11:28

devneeddev

564

asked Nov 15 '18 at 11:28

devneeddev

564

asked Nov 15 '18 at 11:28

devneeddev

564

asked Nov 15 '18 at 11:28

devneeddev

564

Can you use ES6?

– omri_saadon
Nov 15 '18 at 11:29

Just for the sake of interpreting the error, writing: var photos,tags = new Array(); is the same as writing var photos; var tags = new Array();. Hence the error (photos is undefined).

– briosheje
Nov 15 '18 at 11:34

add a comment |

Can you use ES6?

– omri_saadon
Nov 15 '18 at 11:29

Just for the sake of interpreting the error, writing: var photos,tags = new Array(); is the same as writing var photos; var tags = new Array();. Hence the error (photos is undefined).

– briosheje
Nov 15 '18 at 11:34

Can you use ES6?

– omri_saadon
Nov 15 '18 at 11:29

Just for the sake of interpreting the error, writing: var photos,tags = new Array(); is the same as writing var photos; var tags = new Array();. Hence the error (photos is undefined).

– briosheje
Nov 15 '18 at 11:34

add a comment |

2 Answers
2

active

oldest

votes

You're trying to use two arrays there - an array named photos, and an array named tags, so you need to use new Array (or, preferably, ) twice:

var photos = , tags = ;

In your original code, var photos, will result in photos being undefined, no matter what comes after the comma.

If you wanted to create a lot of arrays at once and didn't want to repeat = each time, you could use Array.from with destructuring to keep code DRY:

const [arr1, arr2, arr3, arr4, arr5] = Array.from( length: 5 , () => );

edited Nov 15 '18 at 11:32

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

it works thank you! I will mark as a true answer.

– devneeddev
Nov 15 '18 at 11:30

add a comment |

Using ES6 you can:

let [photos, tags] = [, ];

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

add a comment |

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

You're trying to use two arrays there - an array named photos, and an array named tags, so you need to use new Array (or, preferably, ) twice:

var photos = , tags = ;

In your original code, var photos, will result in photos being undefined, no matter what comes after the comma.

If you wanted to create a lot of arrays at once and didn't want to repeat = each time, you could use Array.from with destructuring to keep code DRY:

const [arr1, arr2, arr3, arr4, arr5] = Array.from( length: 5 , () => );

edited Nov 15 '18 at 11:32

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

it works thank you! I will mark as a true answer.

– devneeddev
Nov 15 '18 at 11:30

add a comment |

You're trying to use two arrays there - an array named photos, and an array named tags, so you need to use new Array (or, preferably, ) twice:

var photos = , tags = ;

In your original code, var photos, will result in photos being undefined, no matter what comes after the comma.

If you wanted to create a lot of arrays at once and didn't want to repeat = each time, you could use Array.from with destructuring to keep code DRY:

const [arr1, arr2, arr3, arr4, arr5] = Array.from( length: 5 , () => );

edited Nov 15 '18 at 11:32

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

it works thank you! I will mark as a true answer.

– devneeddev
Nov 15 '18 at 11:30

add a comment |

You're trying to use two arrays there - an array named photos, and an array named tags, so you need to use new Array (or, preferably, ) twice:

var photos = , tags = ;

In your original code, var photos, will result in photos being undefined, no matter what comes after the comma.

If you wanted to create a lot of arrays at once and didn't want to repeat = each time, you could use Array.from with destructuring to keep code DRY:

const [arr1, arr2, arr3, arr4, arr5] = Array.from( length: 5 , () => );

edited Nov 15 '18 at 11:32

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

You're trying to use two arrays there - an array named photos, and an array named tags, so you need to use new Array (or, preferably, ) twice:

var photos = , tags = ;

In your original code, var photos, will result in photos being undefined, no matter what comes after the comma.

If you wanted to create a lot of arrays at once and didn't want to repeat = each time, you could use Array.from with destructuring to keep code DRY:

const [arr1, arr2, arr3, arr4, arr5] = Array.from( length: 5 , () => );

edited Nov 15 '18 at 11:32

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

edited Nov 15 '18 at 11:32

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

answered Nov 15 '18 at 11:29

CertainPerformance

93.4k165484

it works thank you! I will mark as a true answer.

– devneeddev
Nov 15 '18 at 11:30

add a comment |

it works thank you! I will mark as a true answer.

– devneeddev
Nov 15 '18 at 11:30

it works thank you! I will mark as a true answer.

– devneeddev
Nov 15 '18 at 11:30

add a comment |

Using ES6 you can:

let [photos, tags] = [, ];

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

add a comment |

Using ES6 you can:

let [photos, tags] = [, ];

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

add a comment |

Using ES6 you can:

let [photos, tags] = [, ];

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

Using ES6 you can:

let [photos, tags] = [, ];

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

answered Nov 15 '18 at 11:30

omri_saadon

7,07841546

add a comment |

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